1. Field of the Invention
The present invention relates to a disk player, a turntable, a clamper and a spindle motor which are employed in the disk player, and more particularly, to a disk player provided with a self-compensating dynamic balancer so that internal vibrations due to eccentric mass of a disk can be limited, a self-compensating-dynamic-balancer integrated turntable, a self-compensating-dynamic-balancer integrated clamper, and a self-compensating-dynamic-balancer integrated spindle motor which are employed in the disk player.
2. Description of the Related Art
In general, a disk player is an apparatus for recording information on a recording medium such as a compact disk (CD), a CD-ROM, or a digital versatile disk (DVD), or reproducing information recorded from the recording medium. The disk and an optical pickup are required to be protected against external impact and internal vibrations.
A conventional disk player is shown in FIG. 1. A deck base 10 is hinged to a housing (not shown) to pivot in a vertical direction and a deck plate 20 is attached to the deck base 10. A spindle motor 21, installed at the deck plate 20 to provide a rotational force for a disk 1, has a turntable 23 fixed to a shaft 22 of the spindle motor 21. A disk 1 is placed on the turntable 23. A clamper 40 is installed at the upper inner surface of the housing to face the turntable 23 for clamping the disk 1 on the turntable 23, and an optical pickup 25 is installed at the deck plate 20 to be movable in a radial direction of the disk 1 for performing recording and reproducing operations. The disk player is provided with damper members 30 installed between the deck base 10 and the deck plate 20 so that external vibrations transferred via the deck base 10 are not transferred directly to the deck plate 20, the spindle motor 21 and the optical pickup 25. The damper members 30 are made of a material not having a high strength, such as a soft rubber or polyurethane, so as to absorb external impacts well.
The disk player of FIG. 1 protects the disk 1 and the optical pickup 25 from external impact by employing the damper members 30. However, the disk player of FIG. 1 includes no measures for reducing internal vibrations occurring due to an eccentric mass of the disk 1 where the spindle motor 21 rotates. Here, the eccentric mass of the disk is produced by variations in a manufacturing process of the disk 1. The eccentric mass causes whirling, that is, the revolution of the rotation axis of the spindle motor due to a disparity between the center of rotation of the disk 1 and the center of mass of the disk.
The influence of whirling on the spindle motor 21 is not significant in a low-speed model, such as a base- or a dual-speed model, but the whirling influence is so serious in a high speed model, such as a six-speed or eight-speed model, that recording/reproduction of information can be difficult. To compensate for the whirling influence in a conventional high speed disk player, a deck plate at which a spindle motor is installed is made to have a greater mass, or the damper members are made stronger so that undesirable movement of a deck plate due to an eccentric mass of a disk is reduced.
The effect on whirling of increasing the mass of the deck plate is insignificant where the disk player operates at a high speed. Additionally, an increase in mass increases manufacturing cost, and limits compactness of the disk player. Where the damper members strength is increased, the damper members do not effectively block vibrations and impact transferred from outside the disk player.